A traditional ski comprises a lower surface constituted by a sole edged with longitudinal edges, on which rigid lateral sides rest. The lateral sides are made, for example, of ABS or of phenolic laminate. These lateral sides, which extend over the entire height of the ski, are generally perpendicular to the sole of the ski. Arranged between the lateral sides is the core which can be made in various ways. If appropriate, the core may be made with reinforcement elements, the core itself being covered by an upper wall which likewise rests on the upper wall of the lateral sides.
The advantage of such a ski is that the rigidity of the lateral sides ensures excellent transmission of the forces exerted by the skier on the surface of the snow.
It is more and more frequent, for aesthetic reasons and for reasons of industrialization of the manufacture of the skis, to make shaped skis. The shaped skis may be of non-rectangular cross-section, having a shell which forms the upper face and the lateral sides of the ski. These lateral sides being, if appropriate, inclined over at least a part of their height. In such a case, the core can be made of synthetic foam material, for example polyurethane, which has excellent properties of stability over time as well as being of low weight.